1. Field of the Invention
The current method of solidifying the residue after distillation of solvent refined coal is to spray the hot viscous liquid into a pool of water, which is maintained at a temperature below 212.degree. F. The resulting solid product is found to have a number of undesirable properties. The product which results is highly porous and contains entrapped water at levels as high as from 10 to 30 weight percent. In addition, the porous product is very friable, so as to powder easily. Upon collection, storage, and transportation, fines are produced, which greatly interfere with the use of the product, as well as requiring protection for individuals from inhaling the fines.
Since the solidified residue is the major product, it is desirable to provide the residue in a form which can be readily used as a solid fuel. Therefore, it is necessary that means be provided for forming solid particles in a form which enhances their stability and integrity while still providing a product which burns easily and can be used as a fuel source.
2. Description of the Prior Arts
U.S. Pat. No. 3,748,254 discloses the conversion of solvent refined coal residues to a pelletized solid fuel. U.S. Pat. No. 3,317,289 discloses the manufacture of a smokeless fuel by extracting coal with a solvent, stripping the residue with a stripping agent and then briquetting the residue.